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Gerhard Hoffmann 13 years ago

A these speeds you are mostly talking about integrated versus discrete circuits. Do any of the most recent fpga's meet your needs? They are in 28nm which is blazingly fast but I'm not sure if the i/o would keep up > > Bob

I'm after the fastest possible pulses to drive an electro-optic modulator, with a goal of making light pulses in the 10-100 ps range.

We are using the SERDES blocks of an Altera part to make fast LVDS edges, but the edges are quantized to the SERDES PLL clock, currently 1 GHz. The fastest stuff that I've seen coming out of an FPGA is around 60 ps rise/fall, low level LVDS. Delay temperature coefficients are terrible in FPGAs, so even if you can make fast edges, they drift all over the place.

This is interesting, if expensive.

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auch interessant:

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schönes Wochenende, Gerhard

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John Larkin 13 years ago

The clock-to-output prop delay is 10 ps typ. That's mind boggling. Light travels across the width of the chip in more time than that.

John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

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Gerhard Hoffmann 13 years ago

Ooohps, this one went wrong...

was meant as a email pointer to a colleague until we meet on Monday :-) Thunderbird is !x%$'!!! aargh!

BTW I'll play this weekend with your ramp generator (the one with the AD8009 bootstrap). I have a new Altium Designer installation and choose it as an exercise.

Altium - Camtastic - pdf - offset film from nearby print shop - empty board (self etched & drilled) in a long afternoon.

regards, Gerhard

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Gerhard Hoffmann 13 years ago

Am 09.02.2013 21:51, schrieb John Larkin: ,

travels

And the rise/fall time to the decision point would be 6 ps of this. That means, the "intent" to produce a different output level must travel in 4 ps.

Looks weird. But interesting, nevertheless.

Gerhard

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John Larkin 13 years ago

That seems to be a hazard of using the same program for mail and newsgroups.

What's the application? Fast ramps are fun; fast ramps at 10-12 bit linearity are even more fun.

The inductance of the ramp cap can be an issue if the discharge switch turns off too fast. Sometimes I use a couple of caps in parallel, or slow down the turnoff drive somehow. 1 ns speeds are interesting, but 100 ps is sort of a Chuck Yeager style "wall in the sky."

At some point I got tired of ferric chloride stains on my person. I just breadboard on copperclad, or order a board and do something else until it arrives.

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John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

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John Larkin 13 years ago

travels

If you fudge the threshold definitions a little, you can claim negative prop delay.

John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

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Phil Hobbs 13 years ago

travels

Which sort of suggests that there may be a bit of specsmanship at work.

Cheers

Phil Hobbs

Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 USA +1 845 480 2058 hobbs at electrooptical dot net http://electrooptical.net

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Spehro Pefhany 13 years ago

travels

Resublimated thiotimoline semiconductors?

Best regards, Spehro Pefhany

"it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com

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Jim Thompson 13 years ago

travels

Naaaah! Just resublimated BS. ...Jim Thompson

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John Larkin 13 years ago

travels

Or some imperfectly matched cables.

John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

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Gerhard Hoffmann 13 years ago

Am 10.02.2013 02:08, schrieb John Larkin:

,

or a missing 0 in the tpd spec.

8 risetimes through a master-slave FF seems ok.

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Nico Coesel 13 years ago

travels

Maybe they specced the unpackaged die.

Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico@nctdevpuntnl (punt=.) --------------------------------------------------------------

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josephkk 13 years ago

Light travels

travel

negative prop

I suspect that this one got past you.

You must not be a Dr. A fan.

?-)

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Jasen Betts 13 years ago

hve you installed "xchm" or is help broken in lyspice+wine too?

?? 100% natural

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josephkk 13 years ago

and

I have tried installing xchm and both are still broken. It is very possible i did something wrong though.

?-)

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Jasen Betts 13 years ago

from your descriptions it sounds kind of messed up.

you could try a fresh install by temporarily moving your ~/.wine directory and reinstalling ltspice, if help and works in the new install it's probablly something messed up in your wine install.

also test www with help -> about -> linear-tech-website

It's called a dead hammer because it's got shot in the head

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Fred Abse 13 years ago

I used chm2pdf to convert the LTspice help into a nice indexed PDF.

Better, in fact than LT's own PDF offering.

Xchm doesn't always work with some later editions, beyond the first page.

"For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." (Richard Feynman)

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fast edges

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